Design Methodology.
We put emphasys on the importance of user cognition in the visualization design process [1]} and, taking inspiration by other successful experiences (e.g. [2]})
we applied User-Centered Design (UCD) principles.
Specifically, we followed agile design methodology with brief iteration cycles (1 week sprints).
This process involved 2 developers, and 3 users collaborated in the process by continuously providing feedback on the tool.
Once the tool reached a stable version, we conducted an experiment with an 11-participants focus group and evaluated the usability according to the System Usability Scale (SUS) [3]}.
The results are discussed in Section .
